1. Field of the Invention
The inventive concepts relate to a semiconductor device and a method of fabricating the same.
2. Description of the Related Art
Transistors are widely used in semiconductor devices. For example, millions of transistors may exist on a single integrated circuit (IC). One common type of transistor is the metal oxide semiconductor field effect transistor (MOSFET). MOSFET transistors include p-type channel transistors and n-type channel transistors. A complementary MOS (CMOS) device include both a p-type channel transistor and an n-type channel transistor in a complementary configuration.
One type of semiconductor device that can be fabricated using the CMOS process is a CMOS image sensor (CIS). One problem of the CIS is that a source follower transistor of each pixel has a large amount of random telegraph signal (RTS) noise which can reduce the sensitivity of the CIS. RTS noise may be caused by charge trap/de-trap in a shallow trench isolation (STI) edge that contacts a channel of the source follower transistor. Generally, RTS noise can be reduced by including an enlarged source follower transistor in a CIS. However, including such a large device may undesirable or not possible in some designs.